Standing at the edge of the moon’s shadow, or umbra, the difference between seeing a total eclipse and a partial eclipse comes down to elevation — mountains and valleys both on Earth and on the moon — which affect where the shadow lands. In this visualization, data from NASA’s Lunar Reconnaissance Orbiter account for the moon’s terrain that creates a jagged edge on its shadow. This data is then combined with elevation data on Earth as well as information on the sun angle to create the most accurate map of the eclipse path to date.